Big Apple gardeners may soon have to find a new place to grow their rutabagas if a plan to rescind community-garden rights is implemented.

The Giuliani administration is auctioning off 112 city-owned lots – many used as community gardens – to the highest bidder and has printed public notices for possible investors.

The city’s green-thumb brigades are bracing for another tussle with the Department of Housing Preservation and Development, claiming it’s ignoring a previous policy that garden space would be developed only for housing, if necessary.

Bronx Borough President Fernando Ferrer, a vocal Giuliani critic, said he will introduce legislation this week before the City Council to prohibit auctioned property from being used for any other purpose except housing.

“The city is reneging on a promise it made,” Ferrer said.

“By auctioning these gardens, you’re undermining the community. You don’t have any control over the high bidders. They can end up putting up a parking lot.”

Last April, the city announced it would take over 741 community gardens, to be administered by HPD, in an effort to place them on the tax rolls.

Giuliani defended the program yesterday, saying that housing and commercial uses had to be developed together. He also said protesters knew that the agreement was temporary and their opposition might make it difficult for others in the future.

Public hearings on the next block of properties are scheduled for tomorrow and Jan. 27, with possible auctions in May.